Atheism

Atheism, defined as a philosophical view, is the position that rejects the existence of gods/God/Intelligent Designer/Creator/etc based on the evidence presented by believers. The opposite of atheism is theism.

There is no mention of a concept like atheism in the Qur'an. In general, atheists would likely be lumped together with all other disbelievers simply because they reject the 'Signs of Allah' and reject Prophet Muhammad's claim of being Allah's messenger.

Modern scholars have concluded that atheism is the worst form of disbelief,[1][2] and the vast majority of the world's Muslims[3] believe that atheists are immoral.[4]

↑Note that, according to Pew, unlike adherents of Christianity who are spread out among developed and undeveloped countries, only a tiny 3% of the world's Muslims live in "more-developed regions, such as Europe, North America, Australia, New Zealand and Japan". Meaning, even though this survey does not cover Muslims in America or the western part of Europe, overall it remains a very accurate representation of what the worldwide Muslim population believes (give or take 3% at the most). Indeed, Pew refer to it as a "worldwide survey" of Muslim attitudes. Ref: "The Future of the Global Muslim Population", The Pew Forum on Religion & Public Life, January 27, 2011 (archived), http://www.pewforum.org/The-Future-of-the-Global-Muslim-Population.aspx.